BOULDER — Third in a series of Colorado’s top 5 players in different categories, this time the top 5 as keys to the defense. Reporters were prohibited from watching practices, so these lists were developed after interviewing dozens of players and coaches during fall camp.

Colorado’s Top 5 as keys to the defense:

1. Free safety Ray Polk — The senior must direct traffic in a secondary that has four true freshmen in its two-deep, including starting left cornerback Kenneth Crawley. A three-year starter, Polk (6-1, 205) eagerly took on that task and spent additional time in the film room during the offseason so he could learn the responsibilities of every position in the secondary, including the nickel-back and dime-back.

2. Defensive end Chidera Uzo-Diribe — Quarterbacks in the pass-happy Pac-12 will pick you apart when they have time. The Buffs absolutely, positively need a big junior year from Uzo-Diribe (6-3, 250), their best pass rusher.

3. Linebacker Doug Rippy — Before being felled last fall by a knee injury, the senior from Ohio was CU’s best defensive player. If he hasn’t lost a step or any aggressiveness, his return will be huge for the Buffs.

4. Cornerback Greg Henderson — After earning a starting job last season as a rookie, it’s imperative that the 5-11, 185-pounder have an even more consistent season year as a sophomore. If Henderson can be a shut-down corner on the right side, it will enable CU safeties to help out true freshman Kenneth Crawley on the left size.

5. Defensive tackle Will Pericak — The Boulder native, perhaps best known for the odd “Pre-check” pronunciation of his last name, has been solid throughout his career. Colorado needs him to take the next step and be spectacular. If Pac-12 teams find they can run the ball on the Buffs, it opens up infinite options in the passing game. That’s trouble.

Terry Frei graduated from Wheat Ridge High School in the Denver area and has degrees in history and journalism from the University of Colorado-Boulder. He worked for the Rocky Mountain News while attending CU and joined the Post staff after graduation. He has also worked at the Oregonian in Portland, Ore., and The Sporting News. His seventh book, March 1939: Before the Madness, was issued in February 2014.